If you mean Selenicereus wittll, that's a very rare plant and quite cherished - I would imagine it's quite difficult to find.

There are a few Wittia amazonica plants and one cutting listed on Etsy right now, and one plant on Ebay. I think it's also sometimes named Pseudorhipsalis amazonica. I don't know which name is correct.

I have one that I grew from cuttings I got in a trade, but it isn't large enough yet for me to want to take cuttings from.

I would love to find a Selenicereus wittii!